If your proposed development will be on or near the boundary of your property, I would like to advise you that the Party Wall Act may apply.
The Party Wall act came into force on 1st July 1997, and it covers situations where a building owner wishes to carry out work on a party wall or within 6 metres of an adjoining property.
In brief you must inform your neighbours of the work to be carried out.
14 days notice should be given to an adjoining owner, prior to work commencing, especially where your proposed extension would be adjacent to their existing building.
In the case of foundations, they should be made aware of the fact that any new foundations provided with your extension, may be slightly lower than the those of the existing properties, however you should confirm that you are not proposing to underpin or otherwise strengthen their foundation, and that your extension will not be extending over the boundary in any way. However you may be liable for any damage to the foundations of the adjoining property on the boundary.
In the case of the use of any existing internal Party Wall, you should make them aware of any additional beams or joists that would penetrate part of that walling.
